1. Field of the Invention
The present invention relates to a high-rigidity recliner mounted in a seat for a vehicle, and more particularly to a high-rigidity recliner comprising a pair of symmetrical lock gears fixedly interposed between a cam and a lower actuating member, outer gear parts of the lock gears being engaged with inner gear parts, respectively, so that any clearances between the outer gear parts and the corresponding inner gear parts are eliminated and any irregular engagement of the outer and inner gear parts is prevented, the outer gear parts of the lock gears being formed by means of blanking so that the outer gear parts have high strength.
2. Description of the Related Art
As well known to those skilled in the art, one or more seats are provided in a vehicle, on which a driver or a passenger sits comfortably. In the seat are mounted a pair of seat fixing bases actuated by means of a lever for moving a seat back and forth, and a recliner mounted to the rear end of one of the seat fixing bases for rotating the back of the seat back and forth. The recliner is used for the driver or the passenger to adjust a rotational position of the back of the seat based on his/her body form.
The aforesaid recliner is usually mounted to one side of the seat fixing base to which an actuating lever is attached. When the vehicle collides with another vehicle or any structure, the back of the seat leans forward. At this time, the back of the seat attached to the seat fixing base where the recliner is not provided leans forward, whereas the back of the seat attached to the seat fixing base where the recliner is provided does not lean forward. As a result, a rotational force is generated about the recliner, and thus a repulsive force and the rotational force are applied to the back of the seat when the driver or the passenger is pushed forwardly.
A recliner as shown in FIG. 7 has been proposed in order to solve the aforesaid problems. As shown in FIG. 7, seat fixing bases 1 are provided at both sides of a seat (not shown), and lower fixing members 2 are attached to the rear ends of the seat fixing bases 1, respectively. To the lower fixing members 2 are pivotably attached upper fixing members 4 for controlling a rotating movement of the back of the seat. The recliner comprises a main recliner part 6, to which an actuating lever 10 for adjusting a lock mechanism 5, and a sub recliner part 7 connected to the main recliner part 6 via a cable 8 so that the main and sub recliner parts 6 and 7 are operated simultaneously by means of a link 9.
As described above, the main recliner part 6 and the sub recliner part 7 are operated simultaneously by a tension of the cable 8 connected between the main recliner part 6 and the sub recliner part 7, which requires precise adjustment of the tension of the cable when the cable 8 is assembled into the recliner. Furthermore, if the cable 8 is impacted as the vehicle collides with another vehicle or any structure, a fixing force of the cable 8 at the sub recliner part 7 is released. Consequently, only the main recliner part 6 is operated, with the result that the sub recliner part 7 is rotated about the main recliner part 6.
A recliner as shown in FIG. 8 has been proposed to solve the problems caused by the recliner constructed as shown in FIG. 7. As shown in FIG. 7, lower fixing members 2 are attached to the rear ends of seat fixing bases 1, respectively. To the lower fixing members 2 are pivotably attached upper fixing members 4 for controlling a rotating movement of the back of the seat. The recliner comprises a first recliner part having a lower gear 12 rotated by means of a rotational movement of a cam 13 effected by an actuating lever 10 for controlling a rotating movement of the back of the seat, and a second recliner part connected to the first recliner part via a shaft 14. The second recliner part has a link 15, by which the second recliner part can be cooperated with the first recliner part. At one of the seat fixing bases 1 is provided a nut hole 16, which is close to the lower fixing member 2. A safety belt 17 is fixed to the seat fixing base 1 by means of the nut hole 16.
As described above, the recliner is very complicated in its structure, with the result that the assembly of the recliner is difficult and the cost for manufacturing the recliner is increased. Furthermore, the nut hole provided for fixing the safety belt is formed at the front part of the seat fixing base due to the structure of the lower fixing member. Consequently, the safety belt does not function effectively when the vehicle collides with another vehicle or any structure.
Therefore, a recliner as shown in FIGS. 9 and 10 has been proposed in order to solve the aforesaid problems. As shown in FIGS. 9 and 10, the recliner comprises: a lock gear guiding groove 320 formed inside an upper actuating member 300 by means of blanking, in which a lock gear 500 is operatively arranged; an inner gear part 340 formed on the lower inner edge of the lock gear guiding groove 320 by means of the aforesaid blanking, the lock gear 500 being engaged with the inner gear part 340; a lock gear actuating groove 420 formed inside a lower supporting member 400 by means of the aforesaid blanking; an inner gear part 450 formed on the lower inner edge of the lock gear actuating groove 420 by means of the aforesaid blanking; a reinforcing portion 440 protruded from the lower supporting member 400, the reinforcing portions 440 being inserted into the lock gear guiding groove 320 of the upper actuating member 300, the lock gear 500 being actuated vertically by means of an actuating cam 600 in the lock gear actuating groove 420 of the lower supporting member 400; and a cam hole 540 formed in the lock gear 500, the cam hole 540 having a top end surface 560 and a bottom end surface 580, the top end surface 560 being in contact with a top end 620 of the actuating cam 600 and the bottom end surface 580 being in contact with a bottom end 640 of the actuating cam 600, the actuating cam 600 actuating vertically in the cam hole 540 of the lock gear 500.
The upper actuating member 300 and the lower supporting member 400 are securely fixed to each other by means of the lock gear 500, and the lock gear is actuated in the lock gear guiding groove 320 of the upper actuating member 300 and the lock gear actuating groove 420 of the lower supporting member 400. Consequently, twisting from side to side is reduced as compared to other conventional recliners even when any impact is applied to the recliner as the vehicle collides with another vehicle from the front or from behind, and thus any breakage of the lock gear 500 is prevented. Since the lock gear 500 and the actuating cam 600 are operated only by means of a shaft 700 in the lower supporting member 400, however, there is a clearance between the lock gear 500 and the actuating cam 600, which causes noise and vibration.
Furthermore, an outer gear part 520 is engaged with the inner gear part 450 of the lower supporting member 400 as well as the inner gear part 340 of the upper actuating member 300. Consequently, the assembly operation of the recliner is very difficult, and the engagement of the gear parts may be irregular, which also causes noise and vibration.